New candidate substrate materials for space mirror optics
2019
This paper describes superior candidate substrate material- aluminum nitride (AlN), for the cost-effective and high-performance
requirements for aerospace mirrors. In fact, high specific stiffness and thermal stability are not only two major
considerations to select ideal material but also machinability, dimensional stability, and cost. Silicon carbide shows the
best figure of merits 12627, but it has extremely low remove rate and expensive raw material properties. Extremely low
expansion ceramics such as Zerodur may be difficult to obtain in large quantities and its figure of merit is 1151. On the
contrary, AlN has outstanding thermal conductivity (~170 W/m°C) and maintain high figure of merit 2222 without
compromise. In our fabrication processes, the AlN substrate can be easily polished to 53±1nm Ra surface texture and
66.4±2nm RMS surface form. Its unique thermal stability, specific stiffness, and good figure of merits, associated with its
easy machinability and low-cost raw materials, makes AlN an ideal selection for superior mirror substrate in the future
space mirror optics.
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
12
References
0
Citations
NaN
KQI